diff --git a/transaction.go b/transaction.go
index fe82a7be..e5c51db0 100644
--- a/transaction.go
+++ b/transaction.go
@@ -24,7 +24,7 @@ func (tx Transaction) IsCoinbase() bool {
 }
 
 // SetID sets ID of a transaction
-func (tx Transaction) SetID() {
+func (tx *Transaction) SetID() {
 	var encoded bytes.Buffer
 	var hash [32]byte